With the short (length) wall error messages here is the advice:
Do not create walls less than 300mm, and to try and overlap zones on different levels to avoid slivers of area as well.
Generally the following applies:
- the short wall lengths between 0-150mm generate an error which will not let you simulate until you amend the file.
- The 150-300 now will not generate a warning or an error message. In rare cases the simulation may stall.